Pasco County Sheriff Chris Nocco said at a news conference today that the victim, Chad Oulson, 43, was texting his young daughter's babysitter when an argument erupted with Reeves over texting during previews before the movie "Lone Survivor."

Witnesses of Monday's shooting told police that Reeves and his wife were sitting behind another couple, Oulson and his wife, Nichole, and complained about their text messaging during the movie previews. Reeves went to tell the movie theater managers and when he returned, the argument escalated, according to police.

Reeves said he "was in fear of being attacked" by Oulson so he pulled his .380 semi-automatic handgun from his pants pocket and shot the victim, police said.

"The defendant advised that he got into an argument with the victim over phone usage," the police report from the Pasco County Sheriff's office said. "The defendant advised that the victim turned and stood up striking him in the face with an unknown object."

The sheriff said Reeves' gun jammed after the first and only shot was fired.

Witnesses have told police that someone threw popcorn in the seconds before the shooting and that Nichole Oulson tried to defuse the argument between her husband and Reeves.

Nichole Oulson was wounded in the hand when she put it up to protect her husband, according to the sheriff's office.

Both victims were taken by air to Tampa General Hospital, where Chad Oulson was pronounced dead. His wife was treated for injuries.

Reeves is charged with second-degree murder and is being held without bond. He did not enter a plea.

A judge presiding over Reeves' first court appearance today said the evidence of his guilt was "significant." The prosecutor in the case told the judge that investigators had received a call from another concerned moviegoer who said Reeves had once followed her to the bathroom over her texting.

Reeves' statements raise the possibility that he could try to invoke Florida's "Stand Your Ground" law, made famous by the shooting in which George Zimmerman killed unarmed teenager Trayvon Martin in 2012.

However, the Pasco County Sheriff's Office today called the case murder.

Experts on Florida's controversial law say that Reeves could invoke "Stand Your Ground" as a defense of the shooting, but would have to convince a judge or jury that he reasonably feared for his life and felt he could not retreat, which they said would be a challenge.

"This could be a situation where Stand Your Ground is used. The defendant's statements to police is information that could be used to establish self-defense," said Kenneth B. Nunn, professor of law of the University of Florida's Levin College of Law. "But part of self defense requires you to retreat if you can do so in complete safety."

"Here's the thing," said Bob Dekle, legal skills professor at Levin. "It's not whether or not you're in fear. If the standard about shooting were fear that would give cowards carte blanche. The question is was there reasonable fear, was the fear reasonable?"

Dekle said the defense would be expected to raise the issue before or at Reeves' arraignment.

"If you remember back to the Trayvon Martin case, the defense didn't go forward with Stand Your Ground because the burden of proof was on them to show it was reasonable," Dekle said. In the Zimmerman trial, he claimed self defense and did not invoke the stand your ground law.

Witnesses said they saw the movie theater argument unfolding.

"Somebody throws popcorn. I'm not sure who threw the popcorn," Charles Cummings, who was at the movies as a birthday treat, told the Associated Press. "And then bang, he was shot."

"I can't believe people would bring a pistol, a gun, to a movie," Cummings said. "I can't believe they would argue and fight and shoot one another over popcorn. Over a cellphone."

Oulson's wife is recovering from her hand wound, authorities said.

"She's a wreck. I mean she just lost her husband, the father of her little girl," family friend Joseph Trapani told ABC News affiliate WFTS-TV in Tampa.

An off-duty Sumter County Sheriff's deputy who was in the theater quickly subdued the alleged gunman and took possession of his weapon, police said. The off-duty deputy, who held Reeves until arresting officers arrived, was not immediately identified.

Tampa police identified Reeves as a former captain who retired 20 years ago after helping create the department's Tactical Response Team. Busch Gardens theme park confirmed to ABC News that Reeves was once its director of security.

Police said the alleged shooter and victims did not appear to know one another.